Serial port debrick

[Fridolf]

I made some changes to my PW2 while in diag mode which I got in to with the Rescue pack. After trying to reboot the Kindle froze. All it's showing is the diag screen that was precent when I was trying to reboot.

The orange light is there when trying to do a hard reboot but nothing happens on the screen. When I press the power button for a long time to get it to reboot while connected to the computer it doesn't show up as an USB memory, so I guess trying to get back to diag with the help of the Rescue pack isn't possible?

It was almost fully charged but I did however connect it to a wall charger but it still hasn't changed to the green light after around 20 hours. Will it be a difference if it eventually turn green or doesn't it matter?

And most importantly, if I connect to it via the serial port, will I be able to get into the diag mode again or is the device forever frozen?

I know exactly what changes I did so my thinking is that it will debrick if I can get into diag mode through the serial port and undo the changes. Is this correct or just wishful thinking?

[knc1]

It might be wishful thinking - exactly what changes did you make?

- - - -

PS: what device model are you writing about?
Your info box says PW and the post says PW2 -
It really makes a difference.

- - - -

Note: Try a hard reboot **without** the USB cable connected to anything.

[Fridolf]

Originally Posted by knc1

It might be wishful thinking - exactly what changes did you make?

- - - -

PS: what device model are you writing about?
Your info box says PW and the post says PW2 -
It really makes a difference.

- - - -

Note: Try a hard reboot **without** the USB cable connected to anything.

It's a PW2. I have updated my profile now.

I was messing about with the different numbers. I changed the pcbid and the manufacturing code to the ones I have on my PW1. Bad idea obviously and if this can be fixed I will stop trying stupid things for no reason. That's a promise to myself.

I have tried rebooting it without a cable connected to it by pressing the power button for a long time but the only thing that happens is that the orange light come on but the screen stays frozen.

[knc1]

The battery management chip (and the little green light) is under firmware control normally.
This isn't "normal" operation by any means.

*1* Open the case and disconnect the battery, NOW.
Because: https://www.mobileread.com/forums/sho...49&postcount=3

- - - -

*2* Set up a serial port connection, you are going to need it.
For certain sure, your going to need it.

- - - -

The Kindles are "dual system boot" computers, with very little shared between the two OS installations.
The pcbid, serial number, manufacturing code, etc. are some of the shared information between the two system installations.

Translation:
You have probably bricked both "main" and "diag" mode systems.

Congratulations, your right up there with the people who ask themselves: "I wonder what this 'Erase All' button does?" Just before pushing it. (Hint, the label is descriptive.)

- - - -

Once you have the serial port connection set up, then the next thing to do will be find out if u-boot still works.

Note: It probably does and also probably is refusing to boot either OS because of the corrupted hardware descriptors. The messages it puts out over the serial port will tell us a lot, so be prepared to capture them to a text file.
(The PW and the PW2 use different SoC chips, so swapping the hardware descriptors was doomed from the moment you thought of it.)

But let us know what you find out is happening over the serial port.

[Fridolf]

Originally Posted by knc1

The battery management chip (and the little green light) is under firmware control normally.
This isn't "normal" operation by any means.

*1* Open the case and disconnect the battery, NOW.
Because: https://www.mobileread.com/forums/sho...49&postcount=3

- - - -

*2* Set up a serial port connection, you are going to need it.
For certain sure, your going to need it.

- - - -

The Kindles are "dual system boot" computers, with very little shared between the two OS installations.
The pcbid, serial number, manufacturing code, etc. are some of the shared information between the two system installations.

Translation:
You have probably bricked both "main" and "diag" modes.

Congratulations, your right up there with the people who ask themselves: "I wonder what this 'Erase All' button does?" Just before pushing it. (Hint, the label is descriptive.)

- - - -

Once you have the serial port connection set up, then the next thing to do will be find out if u-boot still works.

Note: It probably does and also probably is refusing to boot either OS because of the corrupted hardware descriptors.
(The PW and the PW1 use different SoC chips, so swapping the hardware descriptors was doomed from the moment you thought of it.)

But let us know what you find out is happening over the serial port.

I have disconnected the battery now and ordered a USB to UART adapter. Hoping for the best but it doesn't look very bright, I guess. Thank you for the information.

[knc1]

Originally Posted by Fridolf

I have disconnected the battery now and ordered a USB to UART adapter. Hoping for the best but it doesn't look very bright, I guess. Thank you for the information.

Not much worse than having pressed 'Erase All' (you aren't the first).

You will need the PW2 pcbid, manufacturing code and serial number - I do hope you wrote them down before you changed them.

Whee.... #7,500

[Fridolf]

Originally Posted by knc1

Not much worse than having pressed 'Erase All' (you aren't the first).

You will need the PW2 pcbid, manufacturing code and serial number - I do hope you wrote them down before you changed them.

Whee.... #7,500

Yes I have everything written down. I will post when I have it connected through the serial port, but in my head it's already dead. Too bad since I guess you can't buy a new one that doesn't have 5.6 and on Ebay it never says what firmware version it has.

[knc1]

Originally Posted by Fridolf

Yes I have everything written down.

That is good.

Originally Posted by Fridolf

I will post when I have it connected through the serial port, but in my head it's already dead.

No, it is recoverable with the above information.
There have been some recent threads about recovering from 'Erase All' - the worst it can get.

Originally Posted by Fridolf

Too bad since I guess you can't buy a new one that doesn't have 5.6 and on Ebay it never says what firmware version it has.

Sometimes you can message the seller and ask, but YMMV on that one.

[Fridolf]

Originally Posted by knc1

That is good.
No, it is recoverable with the above information.
There have been some recent threads about recovering from 'Erase All' - the worst it can get.

Sometimes you can message the seller and ask, but YMMV on that one.

It's nice to hear that there might be some hope. When I read that I probably had bricked both main and diag I felt that I should go on a motherboard hunt.

Yes many sellers don't respond to questions like that even if you tell them where it can be found. Both mine and their loss I guess.

The UART adapter will hopefully arrive before the weekend so I can dig in to this then. Should probably refresh my soldering skills before that.

[Fridolf]

The soldering was really not easy. It's not a great picture but both the RX and 1.8V points are damaged. Is there any other way or is this it?